Burns with patches during MRI

WASHINGTON -- The U.S. Food and Drug Administration Thursday warned of the risk of skin burns in patients wearing transdermal drug patches who are undergoing MRI scans.

Transdermal patches are applied to the skin and can be used to deliver pain medications, hormones and nicotine.

Most of the patches are sold by prescription except for nicotine patches, which are available over-the-counter.

In a public health advisory issued Thursday, the FDA said certain patches contain aluminum or other metal in the backing of the patches which can overheat during an MRI scan and cause skin burns in the immediate area of the patch.

Sandra Kweder, deputy director in FDA's Office of New Drugs, said there are about 60 patches on the market and fewer than 25% of such products have metal in them. She also said some patches that appear clear can contain a metal ion that could also cause a skin burn.

FDA officials said they received two or three reports of skin burns akin to a severe sun burn in patients who wore over-the-counter nicotine patches and underwent an MRI and are investigating a handful of other reports.

Ms. Kweder said the agency is currently reviewing all skin patches and will require those which contain metal to have a warning placed directly on the patch that would likely state, "remove before MRI."

While most of the packaging for patches with metal contains a warning to remove the patch before undergoing an MRI, the agency found that some products, such as Teva Pharmaceutical Industries Ltd.'s fentanyl patch, were missing the warning.

Ms. Kweder also noted that most patients likely won't have the package with them while undergoing the MRI, which is why the agency will require a warning directly on the product as well as on the package.

But until the new labeling is adopted, the FDA said patients and MRI operators should be aware of the risk of skin burns.

The agency said most MRI facilities ask patients whether they are wearing any patches but said patients should also inform health-care professionals when making an appointment for the scan and before undergoing the MRI.